I followed this tutorial https://meta.discourse.org/t/beginners-guide-to-creating-discourse-plugins-part-1/30515. Just installed and worked so guess its clean.
I typed:
bundle exec rails g plugin cidian
EDIT: Capitalization matters in ruby. The name of the plugin created by this generator gets to be a ruby class so that’s why a lower case argument supplied to this generator will lead to a broken plugin.